This invention relates to a molded plastic container having a non-coring, non-leaking piercing site and more particularly to a container in which such a site is integrally formed in said container.
The transfer of medicaments for patient treatment in a hospital or patient care setting between a container and a supply line, or between containers, is frequently accomplished by use of a needle and syringe, a transfer needle, or a needle (or spike) on the end of a solution transfer set.
For the withdrawal or addition of liquid or solution by needle and syringe or by transfer needle to or from a container, a typical container now in use is provided with a rubber stopper with a "thinned" or diaphragm-like section through which the metal needle is inserted. The function of the diaphragm configuration is to provide an entry site capable of being penetrated by the needle and to provide a seal around the needle shaft, and to permit penetration of the rubber without cutting out a small portion or core of rubber by the "heel" of the needle when the latter is thrust through the diaphragm section of the stopper. The supple and elastometric properties of the rubber make this penetration possible.
Lodging of the aforementioned portion or core of the rubber in the lumen of the needle, referred to as coring by the needle, presents the possibility of introducing this "particle" into the blood stream of the patient as well as interfering with the transfer of the solution and is to be avoided.
When a transfer set is employed to transfer solutions from a container to a supply line, a larger diameter plastic needle is generally employed in a manner similar to the use of the metal needle as described above. In this situation, coring by the needle is to be avoided also, but sealing around the needle as it penetrates the stopper is more difficult to accomplish since it has been found that the hole formed by the larger diameter plastic needle tends to be irregular.
Containers currently in use are made of either glass or rigid plastic construction with the rubber stopper or a flexible bag in which there is a fabricated or built-up segment with a tubular appendage to accommodate or support the diaphragm-like membrane to be pierced by the metal or plastic needle.
Such containers currently in use are constructed of separate parts which must be assembled or fabricated. As the contents of the containers are usually sterile and it is necessary to maintain such sterility during the packaging process, it is apparent that there are significant costs involved in componentry and manufacture or processing to produce such a system of providing sterile medicaments to a hospital or patient bedside environment.
Recent developments in the technology of manufacturing plastic containers make it possible that a container can be formed, filled with sterile, non-pyrogenic solution, and sealed under sterile conditions in a single step. Even though machinery to accomplish such a manufacturing process is available, however, it has not been possible up to now to produce a container construction which can be formed in this way which will prevent coring of the needle as it penetrates the container and provide sealing around the shaft of the needle as it is thrust into the container.
Methods and apparatus for the molding and sealing of plastic containers are shown in U.S. Pat. Nos. 3,851,029 and 4,172,534. It is noted that the latter patent does deal with the problem of providing a needle puncture site, but the construction is an expensive one and does not take full advantage of the molding technology now available.